EFFICIENCY IMPROVEMENT OF A COMBINED CYCLE POWER PLANT BY INLET AIR COOLING

Energy conservation and optimization have been the need of the hour especially in industries. Maximizing the output and enhancing the efficiency of various processes are of prime concern.
This paper deals with improvement of efficiency of a combined cycle power plant. Over the years many methods have been proposed for improvement of efficiency of combined cycle power plants like inlet air cooling, supplementary firing, and multi pressure cycles etc. The reason for choosing a particular method for improvement of efficiency of a particular plant depends on various factors like waste heat available in the plant, climatic conditions at the plant location, availability of certain essentials etc.
This is a case study of a combined cycle power plant (NTPC KAWAS) at Surat, Gujarat. It analyses the effect of different operating parameters on the performance of a combined cycle plant. We studied the effect of inlet air cooling on the performance of the cycle. It shows that cooling and bringing down the inlet air temperature increases the mass flow rate and thereby increasing the power output and efficiency of the cycle. The reason for choosing inlet air cooling compared to other methods is that it doesn’t disturb the construction of the existing plant. It will be an additional accessory at the air inlet.
Other factors for choosing this method for improving the efficiency of the combined cycle as mentioned above like climatic conditions etc. and its pros and cons will be discussed in detail in the paper. The aspects like the methods and techniques used to cool the inlet air, Thermodynamic principles and concepts involved, and the economic analysis like the payback period for the proposed method of improving the efficiency will be addressed in the paper. Also the percentage improvement in the gas turbine efficiency and the overall efficiency of the plant will be analyzed in detail in this paper.